In recent years, there has been developed a technique which writes or read data with respect to a Radio Frequency IDentification tag (RFID tag) which is a storage tag (IC tag) including an IC chip and an antenna circuit, in a non-contact manner. Further, such a storage tag is attached to a print sheet, an image is printed on the sheet by a storage tag printer, and data is written to or read from the attached storage tag.
The sheet attached with the storage tag is formed by bonding an IC chip, an antenna circuit, a protective member, and the like onto a sheet base material, so that a position where the storage tag is attached becomes to have a thickness larger than other positions. Therefore, if a plurality of sheets with storage tags are stacked to one another to constitute a sheet bundle, the storage tags attached at the same positions of the respective sheets are stacked, so that the sheets would be curved such that the position is convex. As a result, the sheet bundle becomes bulky, and is inconvenient for conveyance or storage. Further, when the sheet bundle is set in a feed unit of a printer, the sheets are uneven, so the sheets would not be normally fed.